Title :
Bi-directional micro relays with liquid-metal wetted contacts
Author :
Cao, Andrew ; Yuen, P.C. ; Lin, Liwei
Author_Institution :
Dept. of Mech. Eng., California Univ., Berkeley, CA, USA
fDate :
30 Jan.-3 Feb. 2005
Abstract :
Micromachined relays with liquid-metal wetted contacts have been successfully demonstrated using bidirectional electrothermal electromagnetic actuators. MetalMUMPs process, a 6-mask foundry process with 8 thin film layers and a 20μm nickel structural layer, is used to build these relays. Experimentally, the relay can be operated with 0.25 volt and 0.5 ampere and the breakdown voltage and the off-state resistance is greater than 200V and 100MΩ, respectively. The contact resistances of the initial gold-to-gold contacts are around 0.3Ω, while gold contacts wetted with a thin layer of liquid gallium alloy (melting point at -20°C) can achieve contact resistance as low as 0.015Ω. As such, this bi-directional relay can perform single pole double throw (SPDT) function with lower contact resistance using liquid-metal contacts.
Keywords :
contact resistance; electromagnetic actuators; gallium alloys; gold; microactuators; microrelays; nickel; -20 C; 0.015 ohm; 0.25 V; 0.5 A; 20 micron; 6-mask foundry process; Au; Ga; MetalMUMPs process; Ni; bi-directional micro relays; bidirectional electrothermal electromagnetic actuators; breakdown voltage; contact resistance; gold-to-gold contacts; liquid gallium alloy; liquid-metal wetted contacts; micromachined relays; nickel structural layer; off-state resistance; single pole double throw function; Actuators; Bidirectional control; Contact resistance; Electrothermal effects; Foundries; Gold; Microrelays; Nickel; Relays; Transistors;
Conference_Titel :
Micro Electro Mechanical Systems, 2005. MEMS 2005. 18th IEEE International Conference on
Print_ISBN :
0-7803-8732-5
DOI :
10.1109/MEMSYS.2005.1453944